A decoration part includes a skin, a base member and a holding member (a sewing plate), for example. A stitch line is formed on a surface of the skin and the holding member is made of a synthetic resin and arranged between the skin and the base member. The skin and the holding member are sewed together with a stitching thread (a sewing thread) forming the stitch line and the holding member is fixed to the base member (a core member). Accordingly, the skin and the holding member are sewed together with the stitching thread more firmly and surely compared to a configuration in which only the skin is sewed with the stitching thread.